VERNON – Increasing fertilizer prices have producers all over Texas looking for budget-friendly ways to meet their crops’ nutrient requirements, and the upcoming Rolling Plains Summer Crops Field Day on July 17 will feature at least one option, said a Texas AgriLife Research expert.
Dr. Paul DeLaune, AgriLife Research environmental soil scientist, has studied “nitrogen crediting,” a practice where producers use irrigation water as a “free” source of nitrogen for their crops.
DeLaune’s research, conducted at the Texas AgriLife Research and Extension Center in Vernon, has found nitrates already present in Rolling Plains’ irrigation water can provide nitrogen for crops, allowing producers to fertilize crops, save some money and possibly help the environment.
“With nitrogen crediting, irrigators can apply less fertilizer than what is required by a crop and then make up for this deficit with the nitrogen available in their irrigation water,” he said. “By using the nitrogen that is available in irrigation water, a producer can reduce the amount of commercial fertilizer applied.”
DeLaune’s research is part of the Groundwater Nitrogen Source Identification and Remediation project, managed by the Texas Water Resources Institute and funded by the Texas State Soil and Water Conservation Board with Clean Water Act grant funding from the U.S. Environmental Protection Agency.
Area producers can see a living demonstration of nitrogen crediting at the field day, which starts at 7:30 a.m. at the Chillicothe Research Station, located at 1340 Farm-to-Market Road 392 in Chillicothe.
“Our demonstration consists of cotton plants that have received different treatments with and without considering the nitrogen present in the water,” DeLaune said. “So far, our results show applying nitrogen credits does not limit quantity or quality of cotton produced and can lead to substantial savings.”
He said nitrogen crediting is also good for the environment, adding, “Accounting for this available nitrogen in irrigation water has the potential to reduce nitrate levels in local groundwater resources.”
If done on a wide scale, DeLaune said the nitrate levels in the groundwater can be reduced over time, which may result in a decrease in the quantity of nitrate making its way into local creeks.
“Accounting for all sources of nitrogen is the first step in developing a balanced nitrogen budget, which decreases the likelihood of over-applying nitrogen and movement of nitrogen below the root zone,” he said.
DeLaune is working with Dr. Bridget Scanlon, a senior research scientist from the Bureau of Economic Geology at the University of Texas, on this project. Scanlon is evaluating the sources of nitrates in the Seymour Aquifer, which underlies more than 300,000 acres in 20 counties across north Central Texas.
“Previous studies by the bureau suggest that 75 percent of the nitrogen found in the soil is associated with initial cultivation and the subsequent oxidation of soil organic nitrogen from the soil’s surface into the soil column below,” Scanlon said.
“By evaluating carbon and nitrogen isotopes measured deep in the soil profile and pairing the findings with results of artificial tracer studies, our work will help scientists understand how nitrogen moves through the soil and will help in managing groundwater nitrogen levels,” she said.
“This project is scheduled to conclude next summer and will provide area producers with useful information to better manage a valuable, yet often criticized resource,” said Lucas Gregory, the institute’s manager for the project in College Station.
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